Which one of the followings is an incorrect sentence?

The president refuses to accept either of the four new proposals made by contractor

Choose the portion which is not correct in question

We enjoyed the brilliant sunshine of the beach so much and when we left there was only one couple and one lifeguard still there.

Choose the portion which is not correct in question

If a student thinks it's easy to get a chance in the university, he's living in a dream world.

A new battery for domestic appliances in the house is as thin and flexible as paper.

Diversification is a strategy to investing in many unrelated business

You never get a second chance giving a first impression of yourself. No Error.